The Transportation Security Administration is expanding its screening of passengers before they arrive at the airport by searching a wide array of government and private databases that can include records like car registrations and employment information.

While the agency says that the goal is to streamline the security procedures for millions of passengers who pose no risk, the new measures give the government greater authority to use travelers’ data for domestic airport screenings. Previously that level of scrutiny applied only to individuals entering the United States.

The prescreening, some of which is already taking place, is described in documents the T.S.A. released to comply with government regulations about the collection and use of individuals’ data, but the details of the program have not been publicly announced...

The official added that these rules consider things like an individual’s travel itinerary, length of stay abroad and type of travel document, like a passport. If an airline has a traveler’s passport number on file, it is required to share that information with the T.S.A., even for a domestic flight.

The agency also receives a code indicating a passenger is a member of the airline’s frequent-flier program and has access to details about past travel reservations, known as passenger name records. This official could not confirm if that information was being used to assess a passenger’s risk...

Data in the Automated Targeting System is used to decide who is placed on the no-fly list — thousands of people the United States government has banned from flying — and the selectee list, an unknown number of travelers who are required to undergo more in-depth screening, like Mr. Darrat. The T.S.A. also maintains a PreCheck disqualification list, tracking people accused of violating security regulations, including disputes with checkpoint or airline staff members.